Long and short delay fuse



Patented Mar. 29, 1949 UNITED STATES (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 6 Claims.

To provide a fuze that will cause a burst after a delay dependent upon the thickness of the plate penetrated by a projectile wherein the fuze is mounted;

To provide a fuze that will cause bursting of a projectile Within the beam limits of a light armored vessel, but upon impact with heavy armor will delay the burst until after penetration;

To provide a fuze that will, in case of an initial light impact and subsequent heavy impact delay the burst until after cessation of the deceleration due to the heavy impact;

To provide a fuze that will cause the burst of a projectile with a high order of detonation after penetrating armor plate.

In the drawings:

Fig. 1 is a longitudinal section on the axis of a fuze embodying the present invention;

Fig 2 is a longitudinal section of the elements for ring the charge of a projectile after a short delay;

Fig. 3 is a transverse section on the line 3-3, Fig. 1;

Fig. 4 is a longitudinal section of elements for firing the long delay ignition means.

In order to inflict the greatest possible damage upon a target by the explosion of a projectile, it is necessary that the burst be delayed until after the protective armor on the target has been penetrated. It is obvious that if the same type of fuze is to be eiective against both light and heavy craft there must be some provision for causing the burst after the penetration of light armor plate and within a relatively short distance, as when the target is a destroyer, and also to delay the burst until after penetration of heavy armor and travel of the projectile some distance into the space behind the armor to reach the vitals of the ship. Likewise, it is desirable that the fuze be so constructed that if a target have a light protective armor backed by a heavier armor, that the burst should not occur until after penetration of the heavy armor. These requirements are met in a fuze constructed according to the present invention.

The fuze body 5 is provided with a longitudinal bore having portions of diiferent diameters to accommodate the several elements that will be hereinafter set forth. Forwardly of the tracer 6 2 is the rear firing pin carrier 'l wherein is slidably mounted a ring pin 8 having an enlarged rear portion 9 in which is a groove II] and with a conlcal end portion I I. Engaged in the slot I 0 are the detents I2 that are freed from the groove I0 by centrifugal force of rotation of the fuze during flight and when the firing pin is thus freed it creeps forward and allows the balls I3 to drop down behind the end portion I I and so lock the ring pin 8 in its forward or armed position. It is apparent that should any force act upon the ring pin 8 tending to move it backwardly after having been thus locked that the balls I3 would be acted upon simultaneosuly and would mutually prevent each other from being forced back into their original position which would permit the ring pin 8 to be moved out of the armed position.

Forwardly of the firing pin carrier 'I is the rear plunger I4 having an annular groove I 5 adjacent its forward end and in which groove are seated the balls I6 that engage the shoulder I1 on body ,5 and thus lock the rear plunger Ill in its forwardmost position against the pressure of spring I8 that tends to move the rear plunger backwardly. Disposed in the plunger I4 is a firing assembly 5I! comprising a primer I9 that is ignited by contact with firing pin 8 under proper conditions. The gases produced by the burning of primer I9 cause the detonation of primer 22, the resultant hot gases passing through baflle 23 to short delay pellet 24 whence the ignition is propagated by a -body 25 of powder to detonator 26 and thence by detonator lead-outs 21 to booster charges 28.

The forward plunger 29 has at its rear end an annular flange 30 disposed around the balls I6 to act as a ball retainer and thereby prevents displa-cement of the balls I6 except upon impact after flight. Detents 3I lock the plunger 29 in its rearmost portion but are released from engagement with the plunger by rotation of the fuze during flight. A shear pin 32 prevents creeping of plunger 29 after release of the detents 3| until the pin 32 is sheared by movement of plunger 29 upon impact. An expansible ring 33 is disposed is propagated to long delay detonator 4I that in turn ignites the booster charges 42. The gases resulting from the firing of the primers 22 and 31 are prevented from escaping into other parts of the fuze mechanism by obturating rings 43 of lead or other readily deformable metal that are squeezed out into tight sealing contact with the respective plungers, after the Abaffles 23 and 38 are assembled in the respective plungers together with the members wherein the delay elements 24 and 39 are disposed.

The operation of my novel fuze isv as follows:

When fired and while the set back force is acting the ring pin 8 is maintained in the unarmed position as shown in Fig. l, and rear plunger I4 is kept in its forwardmost or unarmed position by the lock effected through engagement of balls I6 in the groove I5 and against the shoulder I'I. After the setback ceases to act the de tents I2 and 3| are moved outwardly by centrifugal force and disengage from the elements respectively locked thereby. The firing pin 3 creeps forward into the armed position and the balls i3' move out and drop down behind the portion lI- and thuslock the firing pin 8 in the armed posi tion. Movement of plunger-s Iii and 2Q is prevented during ilight by the shear wire 32 which re tains plunger 2'9 in position to hold balls i6 in groove I5. Upon striking the target the firing pin 8 is moved forward if it has not already crept into the firing position, forward plunger 29 is moved ahead shearing pin 32, and releasing the balls i5 thereby leaving the rear plunger Iii free to be moved back to strike primer i9 upon firing pin 8 under the force exerted by spring It. However, the inertia of rear plunger I4 holds it forward against the action of springr i8 while the projectile is undergoing deceleration in its passage through an armor plate. If' the armor platev be light the decelerating force ceases to act and spring I8 drives rear plunger i4 backwardly and the; primer I9 is red. The delay intervening between the firing of primer I9 and the detonation. of the charge through detonator 2e and booster 2e' is'sufliciently short that the burst will occur within the beam width of a destroyer.

However if the armor plate be heavy the plunger I'4` will be held in its forward `position by inertia but the primer 3'I will have been fired by firing pin 35 and the long delay burning time of detonator 4 I will result in the burst after passage through the armor and travel of some little distance therebeyond. It may be that if the armor is very heavy delay element 39 will have burned so far by the time penetration is effected that the short delay of the elements carried by rear plunger' I4 will become effective after the deceleration has ceased so that both the firing means will simultaneously act to cause the burst.

In the event that a light plate is penetrated` andvvery soon thereafter a heavyfplate is encountered the plunger I4 will not .have been moved back' into ring position by spring i3A before the deceleration of the heavy impact again moves plunger I4 forwardly and prevents firing of the primer I9. The long delay of the igniting elements in forward plunger 23 will permit penetration of the heavy plate before the burst.

It is thus apparent that a fuze embodying my present invention is effective under various conditions of impact and against substantially a types oftargets. The plungers i4 and 29 are provided with pins44 engaged in corresponding grooves in body 5 to maintain the detonator lead-outs respectively in alignment with the boostn er1 charges to be ignited" thereby. It'willv be obi served that the detonator lead-outs are not in registry with the respectively cooperating booster charges until the plungers have been moved into the ring position and thus the bursting charge of a projectile provided with my fuze would not be detonated even though, for some reason or other, a primer were struck or a. detonator ignited, except when in the ringi position of the plunger and this can occur only after ring of the projectile.

The invention herein described and claimed may be used and/or manufactured by or for the Government of the United States of America for governmental purposes without the -payment of any royalties thereon or therefor.

I claim:

1. A projectile fuze, comprising a fuze body, a rear plunger slidably mounted therein, said plunger havingv an annular groove adjacent its forward end, a detonator charge and associated lead-outs in said plunger; means to ignite said detonator including a rst primer, a second primer disposed to detonate said rst primer. when said second primer is fired; a spring under compres. sion to move said plunger backward, balls in said groove, a shoulder on said body engaging said balls to lock said plunger against movement by said spring; a rst ring pin forwardly slidable in said body toire said second' primer, centrifugally releasable means holding said rst firing pin normally in inoperative position, means to lock said firing pin in ring position; booster charges in said body to register with said leadouts when said plunger is moved back against saidY first firing pin by said spring; a` forward plunger slidable in said body, a rearwardly projecting annular flange on said forward plunger! to retain said balls in said groove when said forward plunger is at its rearmost position, centrifugally releasable means to retain. said forward plunger normally in saidV position, a shearA Wire engaging said body and said' forward plunger to prevent creep of said forward plunger after said centrifugally releasable means have been released, a second detonator and associated leadouts and a third primer in saidforward plungen 2. A- projectile fuze, comprising a fuze body, av

rear plunger slidably mounted therein, said plunger having an annular groove adjacent its`r forward end, a forward plunger slidably mounted in said body, centrlfugally releasable mea-ns no1'- mally retaining said forward plunger in-itsl rear# most position, balls in said groove', a' rearwardly' extending flange on said forward plunger to retain said balls in said groove, a shoulder on said' body engaged by said balls to hold said` rear plunger inl its forwardmost position, a spring? acting to move said rear plunger rearwardly when released by forward movement of said forward plunger, a detonator charge and short delay means including a primer to fire said detonator:

in said rear plunger, a firing pin mounted to' be slidable into positionA to fire said primer'.y cen?.

trifugally releasable means to hold said flring pin normally out of the firing position, means to lock said firing pin in the firing position after release, a detonator and long delay means including a primer to ignite said detonator carried by said forward plunger, a cap on the forward end of said body, a firing pin carried by said cap to fire the primer in said forward plunger when moved forward by impact of a projectile whereby said fuse is carried, a shear pin engaging said body andlsaid forward plunger to prevent creep of said forward plunger, means to lock said forward plunger in the firing position, and booster charges disposed to be fired respectively by said detonators when said plungers are in their respective firing positions.

3. A projectile fuze, comprising a fuze body, a rear plunger slidably mounted therein, said plunger having an annular groove adjacent its forward end, a forward plunger slidably mounted in said body, centrifug .ly releasable means normally retaining said forward plunger in its rearmost position, balls in said groove, a rearwardly extending frange on said forward plunger to retain said balls in said groove, a shoulder on said body engaged by said balls to hold said rear plunger in its forwardrnost position, a spring acting to move said rear plunger rearwardly when released by forward movement of said forward plunger, booster charges in said body, a primer carried by said rear plunger, short delay means to propagate ignition from said primer to said charges, a firing pin slidable into position to fire said primer, centrifugally releasable means to retain said firing pin normally out of firing position, a primer carried by said forward plunger, a firing pin disposed to fire the primer in said forward plunger when moved forwardly, other booster charges, long delay means to propagate ignition from the primer in said forward plunger to said other charges, and a shear pin engaging said forward plunger and said body to prevent creep of said forward plunger after release of said centrifugally releasable means.

4. A projectile fuze, comprising a fuze body, a rear plunger and a forward plunger slidably mounted therein, centrifugally releasable means normally holding said forward plunger in its rearmost position, a shear pin engaging said body and said forward plunger to prevent creep of said forward plunger after release of said releasable means, a rearwardly extending flange on said forward plunger, means cooperating with said flange to lock said rear plunger in its forwardmost position, a spring acting to move said rear plunger rearwardly when released by forward movement of said forward plunger, booster charges, a primer carried by said rear plunger, a firing pin, means normally holding said firing pin in unarmed position but releasable by rotation of said fuze during flight, said firing pin being moved into position to iire said primer not later than impact after night, short delay means to propagate ignition from said primer to said charges, a primer carried by said forward plunger, a firing pin disposed to fire said primer upon forward movement of said forward plunger at impact, other booster charges, long delay means to propagate ignition from the primer in said forward plunger to said other charges, and means to lock said forward plunger in ring position.

5. A projectile fuze, comprising a fuze body, a rear plunger and a forward plunger slidably mounted therein, centrifugally releasable means normally holding said forward plunger in its rearmost position, a shear pin engaging said body and said forward plunger to prevent creep of said forward plunger after release of said releasable means, a rearwardly extending flange on said forward plunger, means cooperating with said ange to lock said rear plunger in its forwardmost position, a spring acting to move said rear plunger rearwardly when released by forward movement of said forward plunger, a primer carried by said rear plunger, a firing pin, means normally holding said firing pin in unarmed position but releasable by rotation of said fuze during flight, said firing pin being moved into position to re said primer not later than impact after flight, short delay ignition propagating means ignitable by said primer, a primer carried by said forward plunger, a firing pin disposed to fire said primer upon forward movement of said forward plunger at impact, long delay ignition progagating means ignitable by the primer in said forward plunger, and means to lock said forward plunger in ring position.

6. A projectile fuze, comprising a fuze body, a. rear plunger and a forward plunger slidably mounted therein, means releasable by rotation of said body during flight to lock said forward plunger in its rearmost position, means including a portion on said forward plunger to lock said rear plunger in its forwardmost position, means to move said rear plunger backwardly when released, a primer in each plunger, a firing pin disposed to fire the one primer upon forward movement of said forward plunger and a second ring pin to lire the other primer upon backward movement of said rear plunger, short delay ignition propagating means ignitable by the primer in said rear plunger, and long delay ignition propagating means ignitable by the primer in said forward plunger.

GEO. M. OREAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 972,425 Wilson et al Oct. 11, 1910 1,046,349 Voller Dec. 3, 1912 1,440,191 Wennerstrom Dec. 26, 1922 1,547,597 Lukens et al. July 28, 1925 1,762,674 Teitscheid June 10, 1930 

